As a major form of international communication, diplomatic discourse is saturated with the culture of national countries and full of struggles for discursive power between multiple cultures on the basis of their unique access to and deployment of discursive resources. Thus, in order to set the basic principles for the construction of China's unique diplomatic discourse, we should take into consideration the struggles of multiple cultures for discursive power, and the construction and maintenance of China's advantageous discursive power in the world. This requires us to break the limitations of Western dualist view of discursive power characterized by zero-game antagonism, uphold a dialectical and social constructionist view, and fully understand the role of diplomatic discourse in the construction of China's international discursive power, so as to make the construction of our diplomatic discourse conducive to the protection of our righteous interest and the promotion of international peaceful development and win-win cooperation. The dialectic intercultural competition analysis advocated by Cultural Discourse Studies (CDS), when adopted as one of the basic theoretic approaches for the construction of China's diplomatic discourse, can help us overthrow the discursive hegemony of Western countries, learn from the diverse cultures in the world, and develop an all-embracing diplomatic discourse system with Chinese characteristics. As discursive power can only be created through the effective possession, selection and utilization of discursive resources, we can decide the principles for the construction of China's diplomatic discourse according to the control and usage of the elemental resources in discursive communication. Specifically, as for the construction of discourse contents, we should create a scientific theory of China's diplomacy based on the in-depth exploration into traditional Chinese culture and integration with the merits of other cultures in the world, and timely proffer topics and solutions of international affairs in accordance with the changing world situations, so as to enhance our content authority over international diplomacy. In terms of participant resources, in addition to continued efforts to improve official, formulaic communication between governmental institutions and persons, efforts should also be made to encourage our non-governmental organizations, institutions, enterprises and common people to engage in public diplomatic activities, and to implicitly popularize our policies and solutions among the mass people of the target countries in their favorite ways. As regards the communication channel resources, while improving the use of traditional media resources such as official press conferences, newspapers and speeches, we can make full use of public mass media resources such as popular books, magazines, movies, TV shows, advertisements and self-media, so as to improve our control over the media channels of our diplomatic discourse. In addition, all the principles and tactics should be integrated into a whole discourse system, so as to ensure that the construction of China's diplomatic discourse system will help improve our discursive power in the world.